Layer of metallomacrocyclic polymer on substrate

ABSTRACT

A layer element comprises a base having a hydrophobic surface and, applied on this, one or more solid, thin, ordered layers of defined uniform and regular structure, in particular monolayers or multilayers, having a uniform orientation of the layer-forming molecules in one direction. The said layers are formed from a metallomacrocyclic polymer which is fusible and/or soluble in an organic, water-immiscible solvent and is of the general formula [M(Pcyc)O] n , where M is Si, Ge or Sn, (Pcyc) is a complex-forming centrosymmetric polycyclic ring system, in particular a phthalocyanine ring system having hydrophobic substituents, and n is the mean degree of polymerization and is equal to or greater than 3. The novel layer elements can advantageously be produced by the Langmuir-Blodgett technique, in which a solid-like monolayer produced on a water surface from the metallomacrocyclic polymers is transferred to a substrate having a hydrophobic surface by immersion and withdrawal of the said substrate. The layer elements according to the invention can be used, for example, as optical filters, e.g. grey filters, interference filters or polarization filters, in electrochemistry and the electrical industry, for example as electrodes, sensors, catalysts etc., as photosensitive elements for electrophotography, and for many other applications.

The present invention relates to layer elements having a base and,applied on this, one or more thin layers in which the molecules areoriented and uniformly distributed on the surface of the base to form anarrangement of high density, in particular a monomolecular layerstructure or multimolecular layer structure, which have a wide varietyof applications. The present invention furthermore relates to a processfor the production of these layer elements.

The production of thin solid layers having a monomolecular ormultimolecular layer structure (frequently also abbreviated tomonolayers or multilayers) on a base or substrate is known. Aconventional method for preparing them is the Langmuir-Blodgetttechnique, in which a high density monolayer which is formed at thephase boundary between water and air and in which the layer-formingmolecules have an oriented arrangement is transferred to a substrate inan ordered state by dipping in this substrate or pulling it out. Thisgives, on the substrate serving as the base, a defined thin solidmonolayer in which the layer-forming molecules are present in an orderedarrangement and uniformly distributed over the substrate surface, withformation of a high density arrangement. By repeating this processseveral times, any number of monolayers can be applied one on top of theother on the substrate, with the result that a multilayer film orcoating is obtained on the substrate surface.

To date, thin solid monolayers or multilayers have been produced usingwater-insoluble amphiphilic compounds having a hydrophilic head groupand a hydrophobic tail, which is generally long-chain. At the phaseboundary between water and air, these amphiphilic molecules form amonolayer in which, when the surface area is reduced, the moleculesbecome oriented so that they are parallel to one another and at rightangles to the surface of the water, the hydrophilic head group being inthe water. The thickness of the monolayers can be varied via the lengthof the side chains of the amphiphilic molecules. As a rule, othermolecules cannot be used since they tend to aggregate or crystallize onthe water surface and the monomolecular nature of the surface layer islost.

Amphiphilic compounds which are particularly interesting for theproduction of monolayers and multilayers include amphiphilicdiacetylenes (cf. inter alia J. Pol. Sci., Polymer Chem. Ed. 17 (1979),1631-1644, EP-A-No. 22 618 and EP-A-No. 77 577). They permit theproduction of well defined polymeric multilayers and can advantageouslybe used for the production of highly sensitive and high-resolution thinphotoresist layers. DE-A-No. 34 44 354 describes photosensitiverecording materials for electrophotography which, in order to achievehigh sensitivity and resolution, contain a photosensitive monolayer ormultilayer film of amphiphilic compounds. In addition to a hydrophilicgroup, for example a carboxyl group, and a hydrophobic group, forexample a long-chain alkyl group, the film-forming amphiphilic moleculescan possess a photosensitive group, e.g. a porphyrin, anthracene orphenanthrene ring or a diazo, polyvinyl or polyacetylene group.According to the Examples of DE-A-No. 34 44 354, polyvinylcarbazolederivatives and copper phthalocyanine are among the substances used forthe production of the photosensitive monolayer or multilayer films.Particularly very recently, the wide range of possible uses ofphthalocyanine compounds has made monolayers of solublemetallophthalocyanines the subject of various investigations (cf. interalia J. Am. Chem. Soc. 106 (1984), 4706-4711 and Nature, 313 (1985),382-384).

The known Langmuir-Blodgett films, i.e. monolayers or multilayers, havea pronounced domain structure, i.e. they are composed of a large numberof small domains. Although, as a rule, the individual domains have anoriented and ordered molecular arrangement, in the entire monolayer ormultilayer the individual domains are arranged in a completely irregularand unoriented manner with respect to one another. Thus, it is true thatsolid thin ordered layers of well defined thickness and high uniformitycan be produced on a substrate by means of these known LB films, but,owing to domain formation, these solid thin layers do not have ahomogeneous, uniform macroscopic structure over the entire layer. Todate, many desirable properties of solid thin layers, which areassociated with uniform orientation of the molecules in the entirelayer, e.g. anisotropy, have been achieved in such solid thin layersonly inadequately and with difficulty, if at all.

It is an object of the present invention to provide novel layer elementswhich possess, on a substrate as the base, one or more solid thin, inparticular monomolecular or multimolecular layers of defined uniform andregular structure and uniform orientation of the layerforming moleculesover the entire solid-thin layer and, because of their structure, have awide variety of advantageous and reproducible properties and hence awide range of applications.

We have found that this object is achieved and that surprisingly, layerelements of this type are obtained if, in order to produce the solidthin layers having a defined structure, metallomacrocyclic polymers areapplied in a suitable manner to a substrate having a hydrophobicsurface.

The present invention accordingly relates to a layer element whichpossesses a base having a hydrophobic surface and, applied on the saidbase, one or more solid, thin, ordered layers having a defined uniformand regular structure with uniform orientation of the layer-formingmolecules in one direction and consisting of a metallomacrocyclicpolymer which is fusible and/or soluble in an organic water-immisciblesolvent and is of the general formula [M(Pcyc)0]_(n), where M is Si, Geor Sn, Pcyc is a complex-forming centrosymmetric polycyclic ring system,in particular a phthalocyanine ring system having a hydrophobicsubstituent, and n is the mean degree of polymerization and is equal toor greater than 3.

The present invention furthermore relates to a process for theproduction of layer elements of the above type by applying one or moresolid, thin layers or defined structure to a substrate as a base,wherein a monomolecular solid-like layer produced on a water surface andconsisting of a metallomacrocyclic polymer which is soluble in anorganic, water-immiscible solvent and is of the general formula[M(Pcyc)0]_(n), where M is Si, Ge or Sn, Pcyc is a complex-formingcentrosymmetric polycyclic ring system and n is the mean degree ofpolymerization and is equal to or greater than 3, is transferred fromthe water surface to a substrate having a hydrophobic surface by dippingthe said substrate in and withdrawing it and, if necessary, repeatingthis process several times.

The present invention furthermore relates to the various embodiments ofthe layer elements and of the process for their production, as describedin detail below.

We have found, surprisingly, that the soluble and/or fusiblemetallomacrocyclic polymers used according to the invention can beemployed to produce, on a hydrophobic substrate surface, well definedsolid thin monolayers or multilayers which do not exhibit domainformation but possess, over the entire layer surface an thickness, auniform and regular ordered structure in which the metallomacrocyclicpolymer molecules forming the solid thin layers are uniformly orientedin one direction. The solid thin layers of the novel layer elementsconsisting of the metallomacrocyclic polymers may therefore also bereferred to and defined as single domain films or single domain layerswhich are in the form of a sort of frozen liquid crystal structure andin which the complex-forming centrosymmetric polycyclic ring systems ofthe metallomacrocyclic polymers are transverse to the plane of the baseor substrate. Regardless of the number of thin monolayers or multilayersarranged one on top of the other on a base, the layer elements accordingto the invention are optically anisotropic as well as thermally verystable and possess advantageous electrical and optoelectricalproperties, so that they are very useful for a very wide variety ofapplications. The fact that it was possible to produce monolayers ormultilayers of well defined uniform and regular structure using thesoluble and/or fusible metallomacrocyclic polymers employed according tothe invention was all the more surprising since the said polymers which,according to the invention, form the solid thin monolayers ormultilayers are not amphiphilic compounds, as are usually employed inthe Langmuir-Blodgett technique (LB technique) for the production ofmonolayers or multilayers.

Suitable bases for the novel layer elements, on which the solid, thin,ordered layers of well defined structure and consisting of themetallomacrocyclic polymers are applied, as any solid, preferablydimensionally stable substrates composed of a very wide variety ofmaterials. The substrates used as bases may be, for example, transparentor opaque to light, electrically conductive or insulating. All that isimportant is that the substrate surface to which the solid thin layer ofthe metallomacrocyclic polymers is applied is hydrophobic. This can beachieved by ensuring that the substrate consists of a hydrophobicmaterial or by rendering the surface of the substrate hydrophobic in aconventional manner by a suitable pretreatment before applying the solidthin layer of the metallomacrocyclic polymers. The hydrophobic substratesurface to be coated should be very clean so that the formation of asolid, thin, ordered layer, in particular a monolayer or multilayer, isnot impeded. For example, the presence of surfactants on the substratesurface to be coated may adversely affect the formation of a goodmonolayer or multilayer. For example, the substrates serving as basescan first be provided with an intermediate layer on their surface to becoated, prior to application of the solid thin layers of themetallomacrocyclic polymers, for example in order to achieve goodadhesion between the solid, thin layer of the metallomacrocyclicpolymers and the substrate. Furthermore, the substrate may be formedfrom different materials in a plurality of strata, provided that theouter surface to which the said layer is to be applied is hydrophobic.

Examples of suitable materials for the substrates used as bases aremetals, e.g. platinum, nickel, palladium, aluminum, chromium, niobium,tantalum, titanium, steel and the like. Other suitable materials for thesubstrates included plastics, such as polyesters, e.g. polyethyleneterephthalate, polybutylene terephthalate, polyvinyl chloride,polyvinylidene chloride, polytetrafluoroethylene etc. Examples offurther suitable materials for the substrates are silicon, glass,silica, ceramic materials and cellulose products, e.g. papers. Thesurface of glass substrates can, if required, be rendered hydrophobic ina conventional manner, for example by reaction with alkylsilanes. Thechoice of substrate materials depends, inter alia, mainly on theintended use of the novel layer elements. For optical elements,transparent substrates which transmit light are generally used as bases.If the novel layer elements are used, for example, in the electricalindustry or in electrochemical processes, particularly useful substratesare electrically conductive materials, such as metals, or materialshaving electrically conductive, in particular metallic, surface layers,for example metallized plastic films. For antistatic treatment, thesolid thin layers of the metallomacrocyclic polymers are applied. to thearticles to be provided with an antistatic treatment, for exampleplastic components, as substrates.

The substrates used as bases for the novel layer elements can have anyform, depending on the intended use. For example, they may be film-like,sheet-like, panel-like, tape-like, disk-like or cylindrical or may beselected from any other forms. In general, the bases are flat, evensubstrates, such as films, sheets, panels, disks, tapes, metal sheetsand the like. The substrate surface to be coated is preferably smooth,as is usual for the production of thin ordered layers having a welldefined structure, in particular monolayers or multilayers. In the caseof the flat even substrates, such as films, sheets, tapes etc., thenovel solid, thin, ordered layers having a well defined structure andconsisting of metallomacrocyclic polymers may be applied on one or bothsurfaces of the substrate. Of course, where the metallomacrocyclicpolymer is applied only to one of the surfaces of the substrate, onlythis surface of the substrate need be hydrophobic.

The layer elements according to the invention contain, applied to thesubstrate serving as the base, one or more solid, thin, ordered layershaving a well defined structure, in particular a monolayer or multilayerstructure, and consisting of a metallomacrocyclic polymer of the generalformula [M(Pcyc)0]n, where M is Si, Ge or Sn, (Pcyc) is acomplex-forming centrosymmetric polycyclic ring system and n is the meandegree of polymerization and is equal to or greater than 3. Thesemetallomacrocyclic polymers used according to the invention arepolysiloxanes, polygermyloxanes or polystannyloxanes, i.e. polymers inwhich the metal atoms covalently bonded to one another via oxygen atomsform the polymer chain, the metal atoms (Si, Ge or Sn) of the polymerchain each being surrounded by a complex-forming, centrosymmetric,polycyclic ring system whose central atom they form. Particularlysuitable polycyclic ring systems are those capable of forming planarcentrosymmetric metal complexes or metal chelates, especially thepolycycles which form planar centrosymmetric N₄ chelates. Examples ofsuch complex-forming, centrosymmetric ring systems are the porphyrin,corrin, hemyporphyrazine and in particular phthalocyanine ring systems.

The metallomacrocyclic polymers used according to the invention forforming the solid thin ordered layers of defined structure should befusible and/or soluble in organic, water-immiscible solvents.Preferably, the said polymers are soluble in organic, water-immisciblesolvents which are readily vaporizable, e.g. chloroform and the like. Toachieve the desired solubility and/or fusibility of themetallomacrocyclic polymers, it is generally necessary for thepolycyclic ring systems of the metallomacrocyclic polymers to carryouter substituents, since metallomacrocyclic polymers of the type underdiscussion whose polycyclic ring system is unsubstituted, for examplethe known unsubstituted phthalocyaninatopolysiloxanes, are, as a rule,insoluble and infusible. Outer substituents are those substituents whichare arranged at the periphery of the polycyclic ring system; they maytherefore also be referred to as oeripheral substituents. Suitable outersubstituents of the polycyclic ring systems are any organic radicalswhich have a hydrophobic effect, i.e. radicals without hydrophilicterminal groups, provided that they render the metallomacrocyclicpolymers soluble and/or fusible or increase their solubility and/orfusibility. The outer substituents of the polycyclic ring systems maybe, for example, aliphatic radicals, for example long-chain alkyl orlong-chain alkoxy groups, aromatic radicals, for example aryl groups, ormixed aliphatic-aromatic radicals, and may furthermore contain heteroatoms, for example ether bonds, or groups containing hetero atoms, forexample carbonyl or sulfonamide groups, provided that these do not havean adverse effect on the hydrophobic action of these outer substituents.The organic radicals for the outer substituents may be linear orbranched and may furthermore be, for example, chiral radicals or groups.The metallomacrocyclic polymers used according to the invention arehydrophobic and insoluble in water.

The metallomacrocyclic polymers used according to the invention forproducing the solid thin ordered layers of defined structure areillustrated in detail below using, as a typical example, thephthalocyaninatopolymetalloxanes which are fusible and/or soluble in anorganic, water-immiscible solvent and are particularly advantageousbecause of the varied and outstanding properties of the novel layerelements produced with them. These phthalocyaninatopolymetalloxanes areof the general formula [M(Pc)0]n, where M is Si, Ge or Sn, (Pc) is aphthalocyanine ring system substituted by a hydrophobic radical so thatthe phthalocyaninatopolymetalloxanes are fusible and/or soluble inorganic, water-immiscible solvents, and n is the mean degree ofpolymerization and is equal to or greater than 3. The phenyl rings ofthe phthalocyanine ring system may each carry one or more, in particular1 or 2, substituents, which should have nonpolar, hydrophobic terminalgroups. The individual phenyl rings of the phthalocyanine ring systemgenerally carry the same substituents. Suitable substituents are theorganic radicals discussed above, which may contain hetero atoms orgroups containing hetero atoms. Preferably, each phenyl ring of thephthalocyanine ring system carries one or more substituents having aterminal, long-chain alkyl radical, in particular of 6 to 30 carbonatoms. In the phthalocyaninatopolymetalloxanes used according to theinvention, the metal atoms from the group consisting of Si, Ge and Snform complex bonds as the central atom in the phthalocyanine ring systemcarrying hydrophobic substituents, the Si, Ge or Sn atoms beingcovalently bonded to one another via one oxygen atom in each case withformation of a polysiloxane, polygermyloxane or polystannyloxane chain.

Phthalocyaninatopolymetalloxanes which are preferred for the productionof the solid, thin, ordered layers of well defined structure in thenovel layer elements are composed of repeating units of the generalformula (I) below ##STR1##

In the general formula (I), M is a silicon, germanium or tin atom and R¹and R² are each a substituent of the type described above, for examplealkyl, alkoxy, alkoxyalkyl, aryl, alkylaryl, aralkyl orsulfonamidoalkyl, or R¹ and R² together may furthermore be a radical ofa fused aromatic ring system, one of the radicals R¹ or R² furthermorebeing hydrogen. Typical examples of R¹ in the general formula (I) arehydrogen, alkyl, e.g. methyl, and alkoxy, e.g. --OCH₃. Typical examplesof R² in the general formula (I) are long-chain alkyl and alkoxy groups,in particular those of 6 to 30 carbon atoms, e.g. --OC₈ H₁₇ or --OC₁₂H₂₅, alkoxyalkylene radicals having a terminal longchain alkyl group of,preferably, 6 to 30 carbon atoms, e.g. --CH₂ --O--C₈ H₁₇, and the --SO₂NHR group where R is a longchain alkyl radical, in particular of 6 to 30carbon atoms.

The mean degree of polymerization of the metallomacrocyclic polymersused according to the invention, expressed by the number n in the abovegeneral formula [M(Pcyc)0]_(n) of the metallomacrocyclic polymers or thegeneral formula [M(Pc)0]_(n) of the advantageousphthalocyaninatopolymetalloxanes, should be not less than 3 butotherwise is not restricted and can vary within wide limits. Forexample, degrees of polymerization up to n =100 are quite possible. Theupper limit of the degree of polymerization is often determined, interalia, by the method of preparation of the polymers and/or the type ofsubstituents in the complex-forming, centrosymmetric polycyclic ringsystem. In practice, we have found that the advantageous and preferredmetallomacrocyclic polymers frequently have a mean degree ofpolymerization of about 4-20.

The soluble and/or fusible metallomacrocyclic polymers of the type underdiscussion can be orepared in a conventional manner familiar to theskilled worker, by polycondensation of the corresponding monomericdihydroxy compounds [M(Pcyc)(OH)₂ ], where M and (Pcyc) have themeanings stated above in connection with the polymers. Tne synthesis ofmetallomacrocyclic polymers whose polycyclic ring system is of courseunsubstituted and the polymers are therefore insoluble and infusible, isdescribed in, for example, Inorganic Chemistry, 2 (1963), 1064-1065, J.Amer. Chem. Soc. 91 (1969), 5210-5214, Adv. Pol. Sci. 50 (1983), 83 etseq and J. Amer. Chem. Soc. 105 (1983), 1539-1550. The correspondingsoluble and/or fusible metallomacrocyclic polymers can be prepared in asimilar manner; in order to introduce the substituents which impartsolubility and/or fusibility, either appropriate substituted startingcompounds are used or the unsubstituted polymers are first prepared andthe substituents are then introduced into the polycyclic ring systems ofthe polymers by polymer-analogous reaction. Because the polymers areprepared by polycondensation of the corresponding monomeric dihydroxycompounds, the metallomacrocyclic polymers used according to theinvention generally contain terminal hydroxyl groups. However, it is ofcourse also possible to use metallomacrocyclic polymers of the typeunder discussion which have other terminal groups, as obtained, forexample, if the terminal hydroxyl groups are blocked by reaction withother compounds.

The solid, thin, ordered layers of defined, uniform and regularstructure which are present in the novel layer elements may be formed byone or more of the metallomacrocyclic polymers. In addition to themetallomacrocyclic polymers, the said layers may also contain othercomponents, in particular the monomeric metallomacrocyclic compoundsfrom which the polymers are derived. Thus, it has been found that novellayer elements whose solid, thin, ordered layers are formed from amixture of the fusible and/or soluble metallomacrocyclic polymers of thegeneral formula [M(Pcyc)0]_(n) and the fusible and/or soluble monomericmetallomacrocyclic compounds from which these polymers are derived, ofthe general formula [M(Pcyc)X₂ ], where M, (Pcyc) and n have the abovemeanings and X is a terminal group bonded to M, in particular hydroxyl,are just as advantageous and, in particular, have optically anisotropicproperties. This was completely unexpected s nce in fact solid, thin,ordered layers which are formed only from the said monomers have apronounced domain structure and are optically isotropic.

The monomers from which the metallomacrocyclic polymers are derived, andwhich likewise should be fusible and/or soluble in an organic,water-immiscible and preferably readily vaporizable solvent are presentin the polymer/monomer mixtures for the solid, thin, ordered layers ofthe novel layer elements in an amount which can vary within wide limitsand is in general about 1-80% by weight, based on the polymer/monomermixture. Novel layer elements having solid, thin, ordered layers ofmixtures of the metallomacrocyclic polymers under discussion and a highcontent of the monomers from which these polymers are derivedsurprisingly still exhibit very pronounced optical anisotropy. Veryadvantageous novel layer elements are those whose solid, thin, orderedlayers consist of a mixture of phthalocyaninatopolymetalloxanes of thegeneral formula [M(Pc)0]_(n), which are fusible and/or soluble inorganic, water-immiscible solvents, and the monomeric compounds of thegeneral formula [M(Pc)X₂ ]from which these polymers are derived; inthese general formulae, as stated above, M is Si, Ge or Sn, (Pc) is aphthalocyanine ring system which carries hydrophobic substituents toimpart fusibility and/or solubility to the compounds, n is the meandegree of polymerization and is equal to or greater than 3 and X is anyterminal group, in particular hydroxyl. Preferably, the said layers ofthe novel layer elements, which are formed from a polymer/monomermixture of the stated type, contain the monomers in an amount of about5-50% by weight, based on the polymer/monomer mixture. The properties ofthe said layers and hence of the novel layer elements, e.g. opticalanisotropy, absorption curves and absorption maxima etc., can be variedand set via the amount of monomers in the said layers of themetallomacrocyclic polymers under discussion.

The solid, thin, ordered layers formed from the metallomacrocyclicpolymers and present in the novel layer elements do not exhibit anydomain formation like the known monolayers or multilayers, but have awell defined, uniform and regular structure over the entire thin,ordered layer or layers. They thus form the single-domain film on thesubstrate surface. In the said layers of the novel layer elements, themetallomacrocyclic polymer molecules forming the thin, ordered layersare oriented uniformly in one direction over the entire layer and arearranged so that the planes of the rings of the polycyclic ring systemsof the metallomacrocyclic polymers are transverse, i.e. at right anglesor at least substantially at right angles, to the plane of the substratesurface serving as a base. Accordingly, the polysiloxane,polygermyloxane or polystannyloxane chains of the metallomacrocyclicpolymers in the said layers of the novel layer elements are parallel orat least substantially parallel to one another over the entire solid,thin, ordered layer and are in a plane, or in planes, parallel or atleast substantially parallel to the plane of the substrate surfaceserving as a base. In the said layers of the novel layer elements, whichare formed from mixtures of the metallomacrocyclic polymers with themetallomacrocyclic monomers from which these polymers are derived, theplane of the rings of the polycyclic ring system of themetallomacrocyclic polymers are parallel to the planes of the rings ofthe polycyclic ring systems of the metallomacrocyclic polymers andtherefore likewise at right angles or at least substantially at rightangles to the plane of the substrate surface. It is therefore to beassumed that the monomers are ordered by the polymer stack and areoriented on the substrate surface in the same way as the polymers. Theuniform and regular layer structure having the uniform molecularorientation in one direction of the solid, thin, ordered layers of themetallomacrocyclic polymers in the novel layer elements can bedemonstrated by the conventional analytical methods usually employed forsuch layers, in particular X-ray diffraction and electron diffractionmeasurements, and is confirmed by the characteristic properties of thenovel layer elements, in particular by their uniform optical absorption,bifringence and dichroism.

The said layers of the novel layer elements of the metallomacrocyclicpolymers possess, in particular and advantageously, a monolayer ormultilayer structure. The layers having a monolayer structure aremonomolecular layers or monomolecular films, i.e. ordered layers offilms consisting of a molecular stratum in which the molecules formingthe layer or film are oriented and uniformly distributed on thesubstrate surface, with formation of a high-density arrangement, asobtained, for example, by the Langmuir-Blodgett method (referred tobelow as the LB method). The solid, thin, ordered layers of the novellayer elements, having a monolayer structure, can be formed from one ormore different types of the metallomacrocyclic polymers underdiscussion, or from mixtures of these with the corresponding monomers.The solid, thin, ordered layers having a multilayer structure aremultistratum layers consisting of monolayers or monomolecular films,i.e. ordered layers in which two or more monomolecular films arearranged one on top of the other on the base. In the solid, thin,ordered layers having a multilayer structure, the individualmonomolecular films can be produced from the same or differentmetallomacrocyclic polymers or the same or different mixtures of thesepolymers and monomers of the type under discussion. Moreover, in thecase of the thin layers having a multilayer structure, it is of coursealso possible for the individual monomolecular films to be formed fromonly one type of molecule or from several different types of molecules(metallomacrocyclic polymers which may or may not be mixed with theparent monomers).

The solid, thin, ordered layers of the novel layer elements are veryhomogeneous, surprisingly heat-stable, optically anisotropic andelectrochemically active. The thickness of these layers can vary withinwide limits, depending on the intended use and the desired propertyspectrum. In the case of the thin, ordered layers having a monolayerstructure, the thickness of the layer is determined by the moleculardimensions and can be varied by the choice of the compounds forming thelayer. In the thin, ordered layers having a multilayer structure, thethickness of the layers essentially depends on the number ofmonomolecular films arranged one on top of the other, this number beingfreely selectable and in principle not restricted. For example, novellayer elements have been produced whose solid, thin, ordered layershaving a multilayer structure were built up from 120 or moremonomolecular films. The novel layer elements may also contain colorsheet and protective layers and/or intermediate layers between the baseand the thin layers and/or the individual strata of thin multistratumlayers.

The novel layer elements are stable to temperatures above 250° C. Onlyabove this temperature do the solid, thin, ordered layers of themetallomacrocyclic polymers exhibit incipient decomposition with theloss of the special and advantageous layer properties. Surprisingly, ithas been found that the properties of the novel layer elements can notonly be stabilized but even improved if the novel layer elements aresubjected to a heat treatment at elevated temperatures, for example atfrom 50° to 200° C., preferably from 100° to 150° C., directly aftertheir production. By means of such a heat treatment, for example, theoptical anisotropy of the novel layer elements can be increased by afactor of 2 or more.

The novel layer elements possessing the solid, thin, ordered layers ofthe metallomacrocyclic polymers can be produced by a conventionalmethod. The LB method is particularly advantageous for this purpose.This metnod employs a water-filled Langmuir trough, i.e. a shallowtrough, for example a rectangular one, which has a movable barrier onone side and a pressure transducer on the other. A certain amount of asolution of the metallomacrocyclic polymers or a solution of themetallomacrocyclic polymer/monomer mixture is applied to the watersurface, and the solvent is evaporated with formation of a monolayer ofthe metallomacrocyclic polymers or of the metallomacrocyclicpolymer/monomer mixture on the water. Thereafter, the surface area ofthe water is continuously reduced by means of the barrier, with theresult that a lateral pressure is exerted on the monolayer on the watersurface, and a solid-like monomolecular film is obtained. Thissolid-like monomolecular film of the metallomacrocyclic polymers, whichmay or may not be mixed with the parent monomers, in which the moleculesare arranged in a type of two-dimensional mesophase and are oriented, isthen transferred from the water surface to a substrate by immersing andwithdrawing the latter. The procedure is usually carried out at about0°-50° C. By repeated immersion and withdrawal, a multimolecular filmcan be formed on the substrate. To produce the novel layer elements, thesubstrate serving as the base is preferably immersed and withdrawn atright angles to the water surface, in order to transfer themonomolecular film produced on the water surface to the substrate. Wherecylindrical substrates are used as bases, the monomolecular film can betransferred from the water surface to the substrate by means of therotating cylinder method, in which the cylindrical substrate is allowedto rotate on the surface of the water.

As stated above, it may be advantageous if, directly after transfer ofthe monomolecular films from the water surface to the substrate, thenovel layer element produced is heated at elevated temperatures, ingeneral at from 50° to 200° C., preferably about 100°-150° C. Althoughthis heating step should be carried out directly after production of thenovel layer elements, storage for a certain time between production ofthe layer elements and heating of the latter is possible if the storagetime is not excessively long, for example not more than a few hours.However, storage times of a few days between production of the layerelements and heating should be avoided. The heating process as such maylast, for example, from a few minutes to a few hours, depending on thetype and thickness of the novel layer elements. By means of the heatingstep following the production of the novel layer elements, theproperties of the said elements can be stabilized or even selectivelyvaried.

Because of their varied and advantageous properties, the novel layerelements have a wide range of uses. As a result of the absorptionproperties and the optical anisotropy of the solid, thin, ordered layersof the metallomacrocyclic polymers, novel layer elements havingtransparent bases can be used, for example, as optical filters, greyfilters, polarization filters or interference filters. Such filtersconsisting of the novel layer elements are independent of temperatureand can be used up to 250° C. Their properties depend on the type of themetallomacrocyclic polymers forming the solid, thin, ordered anisotropiclayer, and on the thickness of this layer. For example, the extinctionof the novel layer elements having a transparent base increases linearlywith the thickness of the said layers. The magnitude of the opticalanisotropy depends not only on the type of metallomacrocyclic polymersor metallomacrocyclic polymer/monomer mixtures used for producing thesolid, thin, ordered layers, but of course also on the wavelength of theincident light. For example, an optical anisotropy, i.e. the ratio o theextinctions of light incident at right angles and parallel to thedirection of molecular orientation in the solid, thin, ordered layers,of from 2 to 6 was measured on novel layer elements at a wavelength of570 nm.

Since, owing to the polycyclic ring systems of the metallomacrocyclicpolymers, the novel layer elements are electrochemically active, i.e.form defined redox states, the said layer elements may alsoadvantageously be used in electrochemistry. For example, in order toproduce sensor or catalyst effects, electrodes, e.g. platinumelectrodes, can be coated with the solid, thin, ordered layers of themetallomacrocyclic polymers to obtain the layer elements according tothe invention. This makes it possible, for example, to eliminateovervoltages at the platinum or to block certain potential ranges forthe electrode. Owing to the defined redox states of themetallomacrocyclic polymers of the type under discussion, electrodescoated with these have windows, in which they are inactive, between theindividual redox potentials of the polycyclic ring system of themetallomacrocyclic polymers. In the novel layer elements, the solid,thin, ordered layers of the metallomacrocyclic polymers generally have aspecific electrical conductivity of about 10¹⁰ ohm⁻¹ cm⁻¹. If thesemiconductor components are used as bases for the said layers of thenovel layer elements, these layers are very useful as insulating layersfor these semi-conductor components. On the other hand, the electricalconductivity of the said layers in the novel layer elements can beincreased by a few powers of ten to the semicoducting range, e.g. fromabout 10⁷ to 10² ohm⁻¹ cm⁻¹, by partial oxidation, for example bytreatment with iodine vapor or by electrochemical oxidation. The saidlayers can thus also be used for the antistatic treatment of articles ifthey are applied, for example as a surface film, to plastic articles,such as windows, gramophone disks, electronic components etc., as bases.The novel layer elements may furthermore be used as photosensitiverecording elements for electrophotography if an electrically conductivesubstrate is used as the base.

The Examples which follow illustrate the invention. Parts andpercentages are by weight, unless stated otherwise.

EXAMPLE 1 (a) Preparation oftrimethoxytetraoctoxyphthalocycaninatopolysiloxane [(CH30)₄ (C₈ H₁₇ O)₄PcSiO]_(n)

7.6 g of CH₃ O--C₈ H₁₇ O--1,3-diiminoisoindolinine in 100 ml ofquinoline were heated to 50° C. under a nitrogen atmosphere. Silicontetrachloride was added, after which the solution was heated at 160° C.for 30 minutes, cooled and then poured into 200 ml of a 1:2water/methanol mixture. The tetramethoxytetraoctoxyphthalocyaninesilicondichloride thus obtained was filtered off under suction, washed withmethanol and dissolved in chloroform, the solution was filtered and thefiltrate was finally evaporated down. Thetetramethoxytetraoctoxyphthalocyaninesilicon dichloride was hydrolysedto the dihydroxide, which was then subjected to polycondensation to givethe desired phthalocyaninatopolysiloxane. To do this, 1 g of thetetramethoxytetraoctoxyphthalocyaninesilicon dihydroxide and 50 mg ofiron(III) chloride in toluene were refluxed for 7 days, while stirring.To check the conversion, samples were taken and absorption spectra intoluene were recorded. When the reaction was complete, the toluene wasstripped off, the phthalocyaninatopolysiloxane was washed with water andmethanol and dried at 50° C. under reduced pressure.

(b) Production of a layer element

100 ml of a solution of the phthalocyaninatopolysiloxane prepared under(a), in chloroform (about 1.6 mg of phthalocyaninatopolysiloxane per mlof chLoroform), were spread out on a water surface of about 60 cm² toform a monolayer, which was compressed to a surface pressure of 20 mN/mby means of a barrier. This lateral surface pressure was kept constantduring transfer of the monolayer to the substrate. The substrate usedfor producing the layer element was a glass plate whose surface had beenrendered hydrophobic beforehand by treatment with dimethylsilicondichloride. The substrate was immersed at right angles and at a speed of8 mm/minute into the water phase covered with the monolayer of thephthalocyaninatopolysiloxane and was withdrawn again. By repeating thisprocess several times, 40 monolayers of the phthalocyaninatopolysiloxanewere applied to each surface of the substrate, so that the glass platewas covered with a total of 80 monolayers.

The absorption spectra in the wavelength range from 500 to 800 nm wasmeasured for the layer element produced under (b), using polarizedlight. In one case the polar axis was at right angles and in anotherparallel to the direction of immersion of the glass plate and hence tothe orientation of the phthalocyaninatopolysiloxane molecules in thelayers. Over the entire wavelength range, a substantially higherabsorption was measured in the case of light incident at right anglesthan in the case of polarized light whose plane of polarization wasparallel to the immersion direction. At the absorption maximum at 560nm, the optical anisotropy (ratio of the extinctions of the layerelement of the light incident at right angles and parallel, reduced bythe intrinsic absorption of the glass) was 2.57.

EXAMPLE 2

As described in Example 1(b), multilayers were prepared on a glass basehaving a surface which had been rendered hydrophobic. In this case,however, the multilayers were prepared using mixtures oftetramethoxytetraoctoxyphthalocyaninatopolysiloxane and monomerictetramethoxytetraoctoxyphthalocyaninesilicon dihydroxide in variousratios. The absorption spectra of the various layer elements wererecorded in polarized light in the wavelength range from 500 to 800 nm,with the polar axis at right angles as well as parallel to the immersiondirection of the glass base. The absorption maximum of the layerelements in this case had been shifted into the range from about 690 to700 nm, i.e. toward the absorption maximum of the monomericphthalocyaninesilicon dihydroxide. The layer elements exhibitedpronounced anisotropy over the entire wavelength range. The opticalanisotropy at 570 nm and 690 nm as a function of the polymer/monomerratio in the mixture is shown in the Table below. The anisotropy valueis the ratio of the optical densities of the layer elements forpolarized light incident at right angles and parallel to the immersiondirection of the glass base, the said optical densities being correctedto take into account the intrinsic absorption of the glass base whichhas been rendered hydrophobic.

                  TABLE                                                           ______________________________________                                        Amount of polymer in                                                                            Optical anisotropy                                          ______________________________________                                        the mixture       at 570 nm                                                                              at 690 nm                                          ______________________________________                                        100%              2.4      2.1                                                66%               2.8      2.0                                                45%               2.5      1.6                                                34%               1.7      1.5                                                ______________________________________                                    

COMPARATIVE EXPERIMENT

The procedure described in Example 2 was followed, except that in thiscase the multilayers were prepared on the glass base using only themonomeric tetramethoxytetraoctoxyphthalocyaninesilicon dihydroxide, i.e.without a polymer. Although it was possible to transfer ordered layersfrom the water phase to the glass base, the resulting layer element wasoptically isotropic.

EXAMPLE 3

The procedure described in Example 1 was followed, except that in thiscase a layer element was produced which contained multilayers consistingof a total of 120 monolayers applied on the glass base. The layerelement was heated to 140° C. immediately after its production and waskept at this temperature for about 1 hour. This heat treatment increasedthe optical anisotropy of the layer element (at 570 nm) from 2.48 to5.82.

EXAMPLE 4

As described in Example 1(a), atetramethoxytetradodecoxyphthalocyaninatopolysiloxane [CH₃ O)₄ (C₁₂ H₂₅O)₄ PcSiO]_(n) was synthesized and was used to apply multilayersconsisting of a total of 40 monolayers to a base consisting of quartzwhich had been rendered hydrophobic. The phthalocyaninatopolysiloxanelayers had an electrical conductivity of about 10⁻⁻¹⁰ ohm⁻¹ cm⁻¹. Themultilayers of the layer element were then chemically oxidized bytreatment with iodine in chloooform, after which excess iodine wasdistilled off azeotropically with chloroform. The layers treated in thismanner had an electrical conductivity of from about 10⁻⁴ to 10⁻⁵ ohm⁻¹cm⁻¹.

EXAMPLE 5

The procedure described in Example 1 was followed, except that in thiscase, instead of the glass plate, a platinum sheet was used as the base,onto which a multilayer consisting of a total of 40 monolayers wasapplied. This layer element was used as an electrode, and acyclovoltammogram was recorded in acetonitrile as an electrolytesolvent. The electrode showed defined reduction and oxidationpotentials. The first reduction potential was at -1.5 V (againstAg/AgCl); the first oxidation potential was at 0.7 V. Owing to thedefined oxidation and reduction potentials of the multilayers of thephthalocyaninatopolysiloxane, no current flowed at a voltage in therange from 0 to -1 V, so that the platinum had been passivated in thispotential window by the applied multilayer of thephthalocyaninatopolysiloxane.

We claim:
 1. A layer element which comprises a base having a hydrophobicsurface and, applied on the said base, one or more solid, thin, orderedlayers having a defined uniform and regular structure with uniformorientation of the molecules in one direction and formed of ametallomacrocyclic polymer which is fusible and/or soluble in an organicwater-immiscible solvent and is of the formula [M(Pcyc)0]_(n), where Mis Si, Ge or Sn, Pcyc is a complexforming centrosymmetric polycyclicring system and n is the mean degree of polymerization and is equal toor greater than
 3. 2. A layer element as defined in claim 1, wherein thesolid, thin, ordered layer or layers contains or contain a mixture ofthe metallomacrocyclic polymers and monomeric metallomacrocycliccompounds of the formula [M(Pcyc)X₂ ], where M is Si, Ge or Sn, Pcyc isa complex-forming centrosymmetric polycyclic ring system and X is aterminal group bonded to M.
 3. A layer element as defined in claim 1,wherein the metallomacrocyclic polymer is aphthalocyaninatopolymetalloxane of the formula [M(Pc)0]_(n), where M isSi, Ge or Sn, Pc is a phthalocyanine ring system having a hydrophobicsubstituent and n is the mean degree of polymerization and is equal toor greater than
 3. 4. A layer element as defined in claim 3, wherein thesolid, thin, ordered layer of the phthalocyaninatopolymetalloxanes alsocontains, mixed with these compounds, monomeric silicon, germanium ortin phthalocyaninatometalloxanes possessing hydrophobic substituents. 5.A layer element as defined in claim 1, wherein the solid, thin, orderedlayers of the metallomacrocyclic polymers have a monolayer or multilayerstructure.
 6. A layer element as defined in claim 1, wherein themolecules of the metallomacrocyclic polymers in the solid, thin, orderedlayers are oriented so that the polymer chains are parallel to oneanother and are in the plane of the layer.
 7. A layer element as definedin claim 1, wherein the solid, thin, ordered layers of themetallomacrocyclic polymers have been heated at from 50° to 200° C.immediately after their production.